| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #pragma once |
| |
| #include <gtest/gtest_prod.h> |
| #include "frameworks/base/cmds/statsd/src/statsd_config.pb.h" // Alert |
| #include "stats_util.h" // HashableDimensionKey and DimToValMap |
| |
| #include <memory> // unique_ptr |
| #include <stdlib.h> |
| |
| namespace android { |
| namespace os { |
| namespace statsd { |
| |
| using std::unordered_map; |
| using std::shared_ptr; |
| |
| // This anomaly track assmues that all values are non-negative. |
| class DiscreteAnomalyTracker { |
| public: |
| DiscreteAnomalyTracker(const Alert& alert); |
| |
| virtual ~DiscreteAnomalyTracker(); |
| |
| // Adds a new bucket or updates an existing bucket. |
| // Bucket index starts from 0. |
| void addOrUpdateBucket(std::shared_ptr<const DimToValMap> BucketValues, int64_t bucketIndex); |
| |
| // Returns true if detected anomaly for the existing buckets on one or more dimension keys. |
| bool detectAnomaly(); |
| |
| // Informs incidentd about the detected alert. |
| void declareAnomaly(); |
| |
| // Detects the alert and informs the incidentd when applicable. |
| void declareAndDeclareAnomaly(); |
| |
| private: |
| // statsd_config.proto Alert message that defines this tracker. |
| const Alert mAlert; |
| |
| // The exisiting bucket list. |
| std::vector<shared_ptr<const DimToValMap>> mPastBuckets; |
| |
| // Sum over all existing buckets cached in mPastBuckets. |
| DimToValMap mSumOverPastBuckets; |
| |
| // Current bucket index of the current anomaly detection window. Bucket index starts from 0. |
| int64_t mCurrentBucketIndex = -1; |
| |
| // The bucket index when the last anomaly was declared. |
| int64_t mLastAlarmAtBucketIndex = -1; |
| |
| // The total number of declared anomalies. |
| int64_t mAnomalyDeclared = 0; |
| |
| // Add the information in the given bucket to mSumOverPastBuckets. |
| void addBucketToSum(const shared_ptr<const DimToValMap>& bucket); |
| |
| // Subtract the information in the given bucket from mSumOverPastBuckets |
| // and remove any items with value 0. |
| void subtractBucketFromSum(const shared_ptr<const DimToValMap>& bucket); |
| |
| // Calculates the corresponding bucket index within the circular array. |
| size_t index(int64_t bucketNum); |
| |
| // Resets all data. For use when all the data gets stale. |
| void reset(); |
| |
| FRIEND_TEST(AnomalyTrackerTest, TestConsecutiveBuckets); |
| FRIEND_TEST(AnomalyTrackerTest, TestSparseBuckets); |
| }; |
| |
| } // namespace statsd |
| } // namespace os |
| } // namespace android |